Fluid pressure brake apparatus



Feb. 20, 1945.

J. CAN ETTA ET AL 2,369,945

FLUID PRESSURE BRAKE APPARATUS Filed Sept. 1 1943 2 Sheets-Sheet 1 JINVENTORS JOHN CANETTA BY CHARLES F. HAMMER ATTORNEY Patented Feb. 20,1945 FLUID PRESSURE BRAKE APPARATUS John Canetta and Charles F. Hammer,Vlilkinsburg, Pa., assignors to The Westinghouse Air Brake Company,Wilmerding, Pa.. a corporation of Pennsylvania Application September 14,1943, Serial No. 502,278

of fluid under pressure from a brake pipe. The

17 Claims.

This invention relates to fluid pressure brakes, and more particularlyto a fluid pressure brake equipment for controlling the application andrelease of the brakes on cars of a railway train.

On railways there are certain cars which are intended to be used inordinary freight train v at the time an emergency application of thebrakes is effected in order to prevent the development of damagingshocks between cars in the train. The AB brake includes a brake cylinderbuild-up control valve mechanism which functions when an emergencyapplication of the brakes is effected, to provide a limited initialinshot of fluid under pressure at a rapid rate to the brake cylinder toquickly apply the brakes with sufficient force to start the slack in thetrain to close or gather. The mechanism then functions to supply fluidunder pressure to the brake cylinder at a relatively slow rate to insurethe gentle gathering of the slack, and finally, said mechanism functionsto provide a more rapid flow of fluid under pressure to the brakecylinder to the full emergency degree to bring the train to a stop. Thiscontrol of brake cylinder pressure is very desirable in that iteffectively prevents harsh gathering or closing of the slack and therebyprevents heavy damaging shocks from being created in a long train.

Modern transportation requirements are such that certain cars equippedwith the AB brake equipment, initially intended only for ordinaryfreight trai service, are now required to operate in relatively shortand high speed passenger, freight or express train service in which therun in or closing of the train slack during emergency applications ofthe brakes does not create damaging shocks, so that an emergencyapplication of the brakes may be effected on such trains at a fasterrate than is deemed advisable in ordinary freight train service, withoutdanger of damage by the shocks created by the run in or closing of thetrain slack.

. The AB brake equipment also includes an emergency portion which, as iswell known by those skilled in the fluid pressure brake art, operatesupon an emergency reduction in brake pipe pressure to supply fluid underpressure from.a quick action chamber to a brake pipe vent valve foreffecting a sudden, local emergency venting fluid under pressure is thengradually released from the quick action chamber through a chokedpassage to permit closure of the vent valve after a period of timesufficient to insure complete venting of fluid pressure from the longbrake pipe on such trains. After closure of these vent valves throughthe train the brakes may be released by recharging the brake pipe on thetrain.

At the present time there are many cars in service equipped with the Ktype brake equipment which was standard before the advent of the ABbrake equipment. Freight trains may therefore comprise some carsequipped with the K equipment mixed in with cars provided with the ABequipment. In the K equipment a complete venting of fluid under pressurefrom the brake pipe in effecting an emergency application of the brakesis not provided for as it is in the AB equipment. In order to insuresaid complete venting on ordinary freight trains it is thereforenecessary that the vent valves of the AB equip-ment be held open, asabove described, for a period of time which is longer than wouldotherwise be necessary and this period of time is excessive andundesirable for shorter trains such as passenger, fast freight orexpress trains, in that at times it might result in an undue delay ingetting such trains under way again following an emergency applicationof the brakes.

Brake equipments for both ordinary freight train service and for shorttrain high speed service are designed to operate on the same pressureratio basis, i. e., to provide equalization oi pressure of fluid in theauxiliary reservoir into the brake cylinder at 50 pounds upon a fullservice reduction in brake pipe pressure of twenty pounds from a normalseventy pounds which is the common standard employed in freight service.However, in high speed trains the normal brake pipe pressure carried isusually one hundred ten pounds and equalization of such a pressure inthe auxiliary reservoir into the brake cylinder would provide anexcessive brake cylinder pressure for a full service application of thebrakes, in that it might cause sliding of the wheels. A safety valvedevice has therefore been heretofore employed on brake equipment used inhigh speed train service to limit the maximum pressure obtainable in thebrake cylinder upon a service reduction in brake pipe pressure to a desgree such as sixty pounds which, under all normal conditions, wouldavoid sliding of wheels.

In effecting an emergency application of the brakes the safety valvedevice is however cut out or rendered uneffective so as to therebyattain the high emergency pressure in the brake cylinder desired toinsure prompt stopping of high speed trains.

From the foregoing it will be understood that for ordinary freight trainservice it is desirable to so control an emergency application of thebrakes as to avoid harsh, damaging gathering of slack. It is alsodesirable to hold the brake pipe vent valves open for a sufiicientperiod of time to insure complete venting of the long brake pipe on suchtrains. On the other hand, the brake equipment employed on relativelyshort trains such as used in passenger, fast freight or express service,should provide for a faster emergency application of the brakes, quickerclosing of the brake pipe vent valves, and requires the use of a safetyvalve for limiting the degree of a service application of the brakes.

One object of the invention is to provide an improved brake equipmentwhich is capable of meeting the above described requirements for bothrelatively slow ordinary freight train service and the shorter, higherspeed train service such as passenger fast freight or express service.

This object is attained by using the AB type of brake equipment with allits operating characteristics which are particularly suited to thecontrol of long freight trains, and by the addition to said equipment ofmeans adapted to operate only in connection with the shorter trainsemployed in fast freight or express service to provide the operatingcharacteristics desired therefor.

Another object of the invention is to provide improved brake equipmentsuch as just described embodying means which is automaticallyadjustable, in accordance with the class of train serv ice in which theequipment is used, to condition the brake equipment to provide thedesired operating characteristics for that service.

Short high speed passenger, freight or express trains are provided witha signal pipe which extends through the train and which is normallycharged with fluid under pressure to provide for the transmission ofsignals from one location in the train to another. Ordinary freighttrains are not so equipped. According to the'last object, the means forautomatically conditioning the brake equipment is arranged for controlfrom the signal pipe, so that when a car provided with the improvedbrake equipment is operated in fast freight or express service it willbe automatically conditioned for such service by the pressure of fluidin the signal pipe. The absence of signal pipe pressure in freighttrains provide, on the other hand, for the automatic conditioning of thebrake equipment for ordinary freight train service.

Other objects and advantages will be apparent from the following moredetailed description of the invention. v

In the accompanying drawings Fig. 1 is a diagrammatic view of a fluidpressure brake equipment embodying the invention. Fig. 2 is anotherdiagrammatic view, mostly in section, showin another form of theinvention.

DESCRIPTION As shown in Fig. l of the accompanying drawings, the brakeequipment comprises a brake controlling valve device I, an auxiliaryreservoir 2, an emergency reservoir 3, a brake cylinder 4, a brake pipe5 and a signal pipe 6.

The brake controlling valve device I comprises a pipe bracket 1, aservice portion 8 mounted on one face of said bracket, and an emergencyportion 9 arranged for mounting on an opposite face of said bracket.According to the invention, the emergency portion is however spaced fromthe bracket 1 by a filling piece or member H) which is mountedlon theopposite face of said bracket and carries the emergency portion 8. Thebrake controlling valve device I further comprises a changeover valveportion l I mounted on the filling piece Ill.

The service and emergency portions 8 and 9 and the pipe bracket 1 may beidentical in all respects to the corresponding parts of the AB brakeequipment fully disclosed in the aforementioned Farmer patent, althoughin the present application only those parts of the portions are shownand will hereinafter be described that are deemed essential to anunderstanding of the invention. The filling piece or member I0 isprovided with suitable through passages connecting correspondingpassages in the pipe bracket 1 and emergency valve portion 9 in orderthat the emergency valve portion will operate in the usual manner.

The service portion 8 comprises a casing containing a piston [8 havingat its face adjacent the pipe bracket 1 a chamber l9 which is inconstant open communication with the brake pipe 5 by way of a passage 20and a connected passage and pipe 2|. At the opposite side of piston l8there is a valve chamber 22 which is in constant open communication withthe auxiliary reservoir 2 by way of a passage and pipe 23. Inchamber 22there is amainslide valve 24 mounted between two spaced shoulders 25 and26 provided on a stem 21' associated with the piston 18. An auxiliaryslide valve 28 is mounted to slide on the main slide valve 24 and isdisposed in a recess provided in the piston stem 21 for movement withsaid stem.

The emergency portion 9 comprises a casing containing a piston 30 havingat its face adjacent the filling piece or member I0 a chamber 3! whichis in constant open communication with the brake pipe through thepassage 20 and connected passage and pipe 2|. At the oppositesideof thepiston 30 there is a valve chamber 32 which is in constant opencommunication witha quick action chamber 33 in the pipe bracket 1,through a passage 34 extending through the filling piece or member l0.Contained in valve chamber 32 is a main slide valve 35 which is looselymounted between two spaced shoulders 35 and 3! provided on a stem 38projecting from the piston 30. An auxiliary slide valve 39 is disposedin a recess in the piston stem 38' for movement therewith and is mountedto slide on the main slide valve 35.

The left-hand end of chamber 32 is closed by a cover 40 having a sleevelike projection 4| in axial relation to piston 30 and in which the endof piston stem 38 is slidably guided. Encircling this extension is anannular chamber 42 of greater diameter than chamber 32 in order toprovide at their meeting ends an annular shoulder 43. A

' plunger 44 is slidably mounted in chamber 42 and is urged by a spring45, also mounted in said chamber, into engagement with the shoulder 43.The piston stem 38 loosely extends through the plunger 44 and isprovided with a shoulder 48 engaging said plunger to define the normalrelease position of the piston 39 and slide valves 3-5 and 39 with theplunger 44 in contact with the shoulder 43. Other functions of theplunger 44 and spring 45 are not pertinent to the invention and furtherdescription thereof will therefore be omitted.

Associated with the emergency portion is a brake cylinder build-upcontrol valve mechanism 59 which comprises a piston slidably mounted ina bore the outer end of which is closed by the cover 40. At theleft-hand side of piston 5| is a chamber 52 connected by a passage 53with a chamber 54 which in turn is connected by a passage 55 to the seatof the emergency main slide valve 35. The chamber 52 contains a spring55 which acts on the piston 5! for urging same in the direction of theright-hand into engagement with an annular seat rib 59. With the piston5i engaging the seat rib 59, a chamber I30 formed around said rib isopen through a passage BI to chamber 52. Within the seat rib 59 is acham ber 52 which is in constant open communication with a chamber 53through a passage 64. The chamber 53 is in constant open communicationwith the brake cylinder 4 through a passage and pipe 65.

The chambers 62 and 63 are separated by a wall 66 through which thepassage 54 extends. A stem 67! having one end connected to the piston 5Iextends through a bore in the wall 66 and through chamber 63 and arelatively large opening 68 into a chamber 69 which is connected by apassage to a brake application and release passage I! one end of whichterminates at the seat for the service slide valve 24 and which is alsoconnected to the seat for the main emergency slide valve 35. In chamber59 the stem 61 engages a check valve E2 and is operative to unseat samefrom an annular seat rib 14, encircling the adjacent end of passage 58,with piston 5! in contact with seat rib 59. A spring I3 in chamber 69 isoperative upon movement of piston 5i away from the seat rib 59 to urgethe check valve '52 into sealing contact with the seat rib 14. Thechambers 63 and 59 are constantly connected through a relativelyrestricted port I5.-

The emergency portion 9 also embodies a timing valve device 8i) whichcomprises a flexible diaphragm 8! clamped between the cover 49 and thepassage 83 and chamber 42 containing the plunger 44. A check valve 84 isassociated with the opposite side of the diaphragm 8i and is adapted tobe urged by the diaphragm under the influence of fluid pressure inchamber 82 into contact with an annular seat rib 85. Within the seat rib85 is a chamber 86 which is in constant open communication with thebrake application and release passage II, Encircling the rib 85 is achamber 8'. which is open through a choke 88 to the brake cylinderpassage 55. Under a condition to be later described, the diaphragm BI isadapted to deflect in the direction of the lefthand to provide formovement of check valve 84 out of contact with seat rib 85 forestablishing communication between the application and release passage'II and the brake cylinder passage 65.

The emergency portion also embodies a brake pipe vent valve device 99which comprises a valve 9| contained in a chamber 92 which is open tothe brake pipe 5 through a passage 93, passage and passage and pipe 21.One side of this valve is arranged to cooperate with an annular seat rib94 for closing communication between the brake pipe chamber 92, and achamber 95 which is open to the atmosphere through a passage 96. Aspring 91 in chamber 92 acts on the valve for. urging same into seatingcontact with the seat rib 94. The valve 9i is connected by means of astem 98 to a piston 99 one side of which piston is subject toatmospheric pressure in chamber 95. At the opposite side of the pistonthere is a chamber I connected by a passage ml to the seat for the mainemergency slide valve 35. The piston 99 is provided with a chokedrelease port I02 which connects chamber IIlI to chamber and there isalso a leakage groove Hi3 provided in the wall of the bore in which thepiston operates for connecting said chambers when the piston is in itsnormal position in which it is shown.

As hereinbefore mentioned the filling piece or member I0 is insertedbetween the pipe bracket I and emergency portion 9 and carries thechangeover valve'portion II. The changeover valveportion embodies acontrol valve mechanism III) which is adapted to be controlled by orconditioned in accordance with the pressure oi fluid in the signal pipe6, and a valve mechanism I II which is adapted to be controlled by orconditioned in accordance with the pressure of fluid in the brake pipe5. 7

The control valve mechanism II!) comprises a flexible diaphragm H5having at one side thereof a chamber I I6 which is in constant opencommunication with the signal pipe 6 through a passage and pipe II'I. Atthe opposite side of diaphragm H5 there is a valve chamber H8 which isin constant open communication with the atmosphere by way of a passageH9.

Contained in valve chamber I I8 is a slide valve I 29 which is connectedthrough the medium of a stem I22 to the diaphragm II5 for movementtherewith, said slide valve being urged against the slide valve seat bya spring I23 acting through the medium of a plunger I24. A spring I25 inthe valve chamber 8 acts on stem I22 for. urging the stem, associatedslide valve I20 and diaphragm II5 to the position in which they areshown in the drawings. This is the position which the slide valve I29will assume in long freight trains on which there is no signal pipe forconnecting to signal pipe 6 of the equipment shown, consequently thissignal pipe 5 will be open to the atmosphere.

When, however, a car equipped with this brake controlling valve deviceis coupled in a fast freight or express train in which a signal pipe isprovided which extends throughout the length of the train, fluid underpressure supplied to said pipe and thereby 'pipe 6 will flow todiaphragm chamber H6 in the changeover portion II. This pressure actingon the diaphragm H5 will deflect the diaphragm in a direction toward theright-hand from the position in which it is shown in the drawings.Deflection of the diaphragm in this direction will. cause the attachedstem I22 and associated slide valve I29 to move in the same directionagainst the opposing pressure of spring I25 until brought to a stop bythe stem I22 engaging a stop I25 on the casing, in which position theywill be maintained as long as the signal pipe 5 is maintained chargedwith fluid under pressure. From the foregoing it will be understood thatthe slide valve I29 has two operating positions namely the position inwhich it is shown for use when a car equipped with this brakecontrol-ling valve device is coupled into. a long freight train, and aposition to the right of that. shown for use. when the car is usedinshort relatively high. speed freight or express train service.

The valve mechanism; II-I comprises a. flexible diaphragm :38 which. isclamped around; its periphery in the casing and which has atone side achamber I3! which is in constant open communication with the brake, pipe5' by way of a passage I32, passage and. passage and pipe. at. At theopposite side of the diaphragm [30 there is a valve chamber I33: whichis in constant open communication with the quick action chamber 33 byway of a passage. L34 and passage 34.

Contained in valve chamber I33 is a slide valve I35 which is connectedthrough the me.- dium of a stem I35 to the diaphragm I30 for movementtherewith, said slide valve being urged against the slide valve seat bya spring I31, acting through the medium of a plunger 30.

Associated with the changeover valve portion I I is a safety valvedevice. I40 which is so adjusted as to limit the degree of a serviceapplication of the brakes. when the brake: controlling valve device isemployed: on a our operating in high speed freight or express service inwhich one hundred ten pounds brake pipe pressure. may be carried; Thesafety valve device I40 is. connected by way of a passage Hi to the seatfor the slide valve 135'.

OPERATION If a car provided with this equipment is coupled into a longfreight train which, as well known, is not provided with a signal pipe,the signal pipe 5 on the car will be devoid of fluid under pressure andchamber IIB at the outer face of the diaphragm [I5 in the control valvemechanism ill) of the changeover portion II will therefore be open tothe atmosphere. Under this condition the spring I acting through themedium of the stem I20 will maintain the slide valve I2il and thediaphragm II5 in'the position in which they are shown. The slide valve428 is provided with a cavity I44 and a cavity Hi5 but in the positionshown for ordinary freight train operation no communications areestablished through these cavities.

In the valve mechanism II I of the changeover portion It the diaphragm Iis controlled by the opposing pressures of the quick action chamber andthe brake pipe. Since these pressures are equal when the equipment ischarged with fluid under pressure, as hereinafter described, thediaphragm I30 and associated stem I36 and slide valve E will bemaintained in the position shown so long as brake pipe pressure inchamber 23! is not reduced enough below quick: action chamber pressurein chamber I33 to permit the quick action chamber pressure to overcomeslide valve friction and move the diaphragm and thereby the slide valveinto a position to the left of that in which it is shown in Fig. 1. Theonly communication established with the slide valve in its normalposition as shown is through a cavity I49 between passage I 4| leadingto the safety valve M0 and a passage I50 leading to the seat for theslide valve I20= in the control mechanism lid of the changeover valveportion, but this is of no consequence at this time since the passageE50 is lapped by slide valve I20 as shown.

With the changeover valve portion II of the Ill:

aaeaew brake controlling valve device I conditioned as shown inv thedrawings; due to the lacl: of signal pipe pressure in diaphragm chamberI I6, no communications are established which will in any way change theoperation of the AB brake equipment. Thus in ordinary freight trains thebrake equipment on the car will operate to provide the desired operatingcharacteristics for that class of service as described in theaforementioned Farmer patent, but which will now be set forth briefly.

ORDINARY FREIGHT TRAIN SERVICE-INITIAL CHARGING To initially charge thebrake equipment fluid under pressure is supplied to the brake pipe 5 inthe usual manner and flows therefrom through pipe and passage 2: andpassage 20 to the service piston chamber chamber 3!. Fluid underpressure thus supplied to passage 2i also flows through passage 93 tothe vent valve, chamber 92' and through passage I32 to chamber l3I- inthe valve mechanism III of the changeover valve portion II to chargethese chambers with fluid at brake pipe pressure.

With the several parts of the service portion 8 in their normal releaseposition as shown in the drawings, fluid under pressure supplied tochamber M) will flow around the piston I8 through feed groove I5 to thevalve chamber 22 and thence through passage and pipe 23 to the auxiliaryreservoir 2. Fluid under pressure also flows from chamber to theemergency reservoir 4 by way of a port I-52 in the main slide valve 24,a passage I53 and a passage and pipe I54.

In this position of the main slide valve 24 the brake cylinder 4 is opento the atmosphere through pipe and passage 65, chamber 63 in the delayvalvev mechanism 53,, past the check valve 1'2 to chamber 39 and thencethrough passages I0 and 'II, a release cavity I55 in the main slidevalve 24 and passage 156 which leads to the atmosphere.

With the several parts of the emergency portion 0 in their normalrelease position as shown, fluid under pressure supplied to the pistonchamber 35 will flow therefrom through a restricted feed port I58 topassage 3d and through said passage in one direction to the emergencyvalve chamber 32 and in the opposite direction to the quick actionchamber 33. Fluid under pressure thus supplied to passage 34 will alsoflow therefrom to the valve chamber I33 in the changeovervalv portion IIby way of passage I34. With the valve chamber i33 thus charged withfluid under pressure at quick action chamber pressure and the chamberI3! at the opposite side of diaphragm charged with fluid at brake pipepressure, the diaphragm 53d, stem I36 and slide valve I35 will bemaintained in its normal position in which it is shown so long as brakepipe pressure in chamber i3'I is not reduced enough below quick actionchamber pressure in chamber I33 to permit the quick action chamberpressure to overcome the friction of the slide valve I 35.

With the main emergency slide valve 35 in its normal position as shown,passage IOI is connected to a port IM in said slide valve which leads tothe seat for the auxiliary slide valve 39 where it is lapped or closed.Under this condition chamber tilt at the left-hand side of the ventvalve piston 99 will be atmospheric pressure clue to the connectionthrough port I02 and groove I63 with chamber which is open to theatmosphere. As a result spring 91 will hold the IQ and the emergencypiston vent valve 9! seated against rib 94 so that chamber 92 will becharged with fluid at brake pipe pressure.

With the emergency main slide valve 35 in its normal position as shown,a cavity 465 therein connects passage 55 to the brake application andrelease passage H which is open to the atmosphere through the serviceslide valve 2t, as above described. As a result, chamber 54 and therebyconnected chamber 52 will both be at atmospheric pressure, and sincechamber 62 at the opposite side of said piston is open to the atmospherealong with the brake cylinder l,

spring 56 will be efiective to hold the piston 5| in engagement withseat rib 53 to thereby position stem 61 for holding the check valve 72out of contact with the seat rib 14. Chamber 86 at one side of thetiming valve diaphragm 8| is at this time open to the atmosphere throughthe application and release passage H and thence by way of the serviceslide valve 23, while chamber application of the brakes, the cavity I65connects the passage 1 I to passage 55, so that fluid supplied topassage ll will flow to chamber 54 and thence 8'! encircling said rib isalso open to the atmosphere at this time by way of port 88' and passage65 along with the brake cylinder 4. As a result, the pressure of fluidfrom the emergency valve chamber 33, efiective in chamber 82 on theopposite side of the timing valve diaphragm 8i, will hold the checkvalve 8 1 in sealing engagement with the seat rib 35 to thereby closecommunication between chambers 86 and 8'! within and around,respectively, the seat rib 85.

GRnINARY FREIGHT TRAIN SERVICE-SERVICE APPLICATION or BRAKES With theequipment fully charged as just described, if the engineer desires toeffect a service application of the brakes, he will eiTect a servicereduction in the pressure of fluid in brake pipe 5, in the usual wellknown manner. The pressure oi fluid in piston chamber IQ of the serviceportion 8 will then reduce at a service rate along with the reduction inpressure of fluid in brake pipe 5, and since this rate is in excess ofthat at which auxiliary reservoir pressure in valve chambe 22 can reduceby flow back to chamber l9 through feed groove 15, a difierential ofpressure will be created on the piston 18 which will ,effect movementthereof to its service application position defined by contact betweensaid piston and the left-hand end of the bore in which the pistonoperates.

As the service piston I8 is thus moved in the direction of itsapplication position, it initially moves the auxiliary slide valve 28relative to the main slide valve 24 for closing communication betweenthe emergency charging port 552 and valve chamber 22 and for openingcommunication between said valve chamber and a service application port95? in the main slide valve 24'. At substantially the same time as theservice port I6! is thus opened to the valve chamber 22, the shoulder 25on the piston stem 2'! engages the end of the main slide valve 24. Thepiston as it moves further toward its service position will now movesaid main slide valve to its service position in which the service portit! registers with the brake application and release passage H.

Fluid under pressure will then flow from valve chamber 22 and therebythe connected auxiliary reservoir 2 to the application and releasepassage "ll and thence through passage iii to check valve 69 in thedelay valve device 50 and also to the seat of the emergency main slidevalve 35. With the slide valve 35 in its normal position as shown, inwhich it will remain during a service through passage 53 to chamber 52at the lefthand side of the delay valve piston 5|. At the same time thisoccurs, fluid under pressure su pplied to the check valve chamber 69will flow past the check valve 72 to chamber 63 and thence throughpassage 54 to chamber 62. The fluid pressure thus acting on oppositesides of piston 5! will be balanced so that spring 56 will, under thiscondition, maintain the piston in its righthand position as shown andthereby maintain the check valve 12 in its unseated condition as shown.The fluid under pressure supplied from the auxiliary reservoir to thecheck valve 69 will therefore flow past the check valve i2 through therelatively large opening 68 to chamber 63 and thence through passage 65to the brake cylinder 4 for effecting a service application of thebrakeson the car.

. Fluid under pressure will continue to flow from the auxiliaryreservoir to the brake cylinder 4 until 'the auxiliary reservoirpressure in valve chamber 22 becomes reduced to a degree slightly lowerthan the reduced brake pipe pressure effective in piston chamber it, ifthe reduction in brake pipe pressure is less than a full servicereduction, the piston It will then be moved by brake pipe pressuretoward the right-handrelative to the main slide valve 34 for shiftingthe auxiliary slide valve 28 to a lap position for'closing communicationbetween valve chamber 22 and the service application passage it! in themain slide valve 24.

'The degree of pressure obtained in the brake cylinder 4 will thus belimited in accordance with the degree of service reduction in brake pipepressure efiective in piston chamber 19. If less than a full servicereduction in brake pipe pressure is effected, a further reduction willefiect in brake pipe pressure, which in ordinary freight train servicewill be a 20 pound reduction from a normal pounds pressure in the brakepipe. U-pon such a reduction in brake pipe pressure, the pressure offluid in the auxiliary reservoir 2 will equalize into the brake cylinder4 at substantially 50 pounds.

Upon a service reduction in brake pipe pressure in piston chamber 3! ofthe emergency portion 9, the emergency pist0n.30 will move toward theright-hand to shift the auxiliary slide valve 39 relative to, the mainslide valve 35 to a position in which a port I68 in the auxiliary slidevalve registers with a port 139 in the main slide valve, the ort 69 inturn registers with an at-- mospheric vent port H5 with the main slidevalve in its normal position as shown. Through this communication fluidunder pressure will flow from the valve chamber 32 and quick actionchamber 33 at the same rate as the service rate of reduction in brakepipe pressure in piston chamber 3 i, whereby movement of the piston willbe stopped without shifting the main slide valve 35. When the pressurein valve chamber 32 and quick action chamber 33 is thus reduced to adegree slightly below the brake pipe pressure effective in pistonchamber 3| the emergency piston 39 will be moved toward the left-handand thereby shift the auxiliary slide valve 39 back to its normalposition shown for closing communication between port lSS therein andport I-39 in the main slide valve to thereby limit the reduction inpressure in said chamber to substan- I tia'lly the same 'degree as thatof the brake pipe. In other words, upon aservice reduction in brake pipepressure the emergency portion will operate only to reduce the pressurein the valve chamber 32 and quick action chamber 33, in accordance withthe reduction in the brake pipe pressure.

Upon a service rate of reduction in the pressure of fluid in brake pipe-and quick action chamber 33, as just described, the pressure of fluidin chambers I3I and 33 at opposite sides of the diaphragm I30 in thevalve mechanism I-I-E of the changeover valve portion H is alsoreduced.The flow of fluid under pressure from chamber I3I to the brake pipe isby way of passages I32 and and passage and pipe 2|. The flow of fluidunder pressure from chamber I33 is by way of passage I34, passage 34,emergency valve chamber 32, port 168 in the auxiliary slide valve 33,port I 59 in the main slide valve 35 and port IIll. It will be notedthat the pressure of fluid in chamber I33 reduces with the pressure offluid in emergency valve chamber 32, which latter pressure reduces atthe same rate as the pressureof fluid in chamber I-3I is reducedduringaservice application-of the brakes, and thereby prevents obtaining asufiicient differential of pressures on the diaphragm I36 to cause saiddiaphragm to deflect from the :position in which it is shown.

From the foregoing description it will be understood that upon effectinga service reduction in brake pipe pressure the brake pipe pressure inchamber I3! and quick action chamber pressure in chamber I33 in thechangeover valve portion II will be reduced at the same rate and thatthe diaphragm I30, stem I36 and slide valve I35 will remain in theposition shown. Thus in ordinary freight train service the changeovervalve por tion .I i will remain inoperative and the brake controllingvalve device I will operate as above described to provide a serviceapplication of the brakes in harmony with the other cars in the train.

ORDINARY FREIGHT TRAIN SERVICE-RELEASE or BRAKES AFTER A SERVICEAPPLICATION To effect a release of brakes after a service application,fluid under pressure is again supplied to the brake pipe 5 to restorethe brake pipe pressure to the normal degree. crease in pressure inbrake pipe 5 the pressure in chamber I3-I of the changeover valveportion ll is increased through the circuit hereinbefore traced in thedescription of initial charging. The consequent increase in pressure inthe piston chamber l9 will move the service piston I8 and thereby theslide valves 24 and 28 back to their normal position in which they areshown. In this position the auxiliary reservoir 2 and emergencyreservoir 3 Will be recharged with fluid under pressure from the brakepipe and the brake cylinder 4 will be opened to the atmosphere foreffecting a release of the brakes, as above described in connection withinitial charging of the equipment. The emergency portion provides forthe restoration of the pressure in valve chamber 32, quick actionchamber 33 and connected valve chamber I33 in the changeover valveportion II as the brake pipe pressure is increased to that normallycarried.

As a result of an in- :a-seaece The :brakes "on the train will now bereleased and the brake system fully recharged with fluid under pressurefor a subsequent brake operation. as will be apparent.

ORDINARY FREIGHT TRAIN SERVICE-EMERGENCY APPLICATION or THE BRAKES Ifthe engineer desires to effect an emergency application of the brakes,he will initiate, at the locomotive, a'sudden emergency reduction inpressure of fluid in the brake pipe 5 in the usual manner. In "responseto this reduction in brake pipe pressure the service portion of thebrake control-ling valve device I functions to supply fluid underpressure from the auxiliary reservoir 2 to the brake cylinder 4 in thesame manner as hereinbefore described in connection with a serviceapplication of the brakes. If the brake controlling valve device I is onthe car next to the locomotive, the emergency piston 30 therein willrespond to the reduction in the brake pipe pressure initiated by theengineer and move the auxiliary slide valve 39 relative to the mainslide valve to its service position above described in which ports I68and IE3 are in registry. The flow capacity of these ports is howeverinsufficient to reduce the pressure in valve chamber 32 and quick actionchamber 33 as fast as the brake pipe pressure is being reduced, so thata differential of pressure will be promptly obtained on the emergencypiston for moving same from service position to an emergency position atthe righthand end of the bore in which it operates. During this movementof the piston 30, the shoulder .31 at the left-hand end of the pistonstem 38 will engage the main slide valve 35 and move it to emergencyposition. 7

At the time shoulder?! on the piston stem 38 engages the main slidevalve 35, the auxiliary slide valve 39 opens passage I64 to valvechamber 32. This passage at the seat for the main slide valve registerswith passage IOI leading to the vent valve piston chamber I00, so thatflow of fluid under pressure from valve chamber 32 and. quick actionchamber 33 to the vent valve piston chamber I00 will occur. When themain .slide valve 35 is however moved to its emergency position passageIOI isopen past the end of slide valve 35 to chamber 32 to provide forfurther 'flow of fluid under pressure to the vent valve piston chamberI00.

The :pressure of fluid thus obtained in chamber I00 on the face of thevent valve piston 99 will effect movement of said piston in thedirection of the right-hand to move the brake pipe vent valve 9| out ofcontact with seat rib 94, thereby opening communication between thebrake pipe passage 93 and chamber 35 which is open to the atmospherethrough passage 36. Through this communication fluid under pressure willthen be vented from the brake pipe at an emergency rate for causing theemergency portion '9 on the next car in the train to operate in the-samemanner as above described, and thus propagate the emergency-actionthrough the train in theusual manner.

In the emergency position of the emergency piston 30 and main slidevalve 35, the passage '55 is lapped by said valve so as to prevent theflow of'fluid under pressure to chamber 54 and chamber 52 at theleft-hand side of the delay valve piston 5|. ,At the same time as thisoccurs, passage I54 connected to emergency reservoir 3 is opened throughcavity I55 in-said valve to the application and release passage "II, sothat both the auxiliary and emergency reservoirs are placed incommunication with said passage and thereby with passage is leading tocheck valve chamber 89 in the delay valve mechanism 56. Fluid un- (181pressure thus supplied to check valve chamber iii] from both theauxiliary and emergency reservoirs will then flow past check valve I2through the relatively large opening 68 to chamber 53 and thence throughpassage $5 to the brake cylinder i for initiating the emergencyapplication of the brakes.

At the same time as fluid is thus supplied to the brake cylinder fromchamber 63, fluid also flows from said chamber through passage 64 tochamber (52 at the right-hand face of the delay valve piston 5!. Underthis condition, chamber 52 at the opposite side of piston in is notsupplied with fluid under pressure so that only the pressure of spring58 on said piston will oppose the pressure of fluid in chamber 32 theopposite side of the piston. The pressure of spring 555 is such thatwhen the pressure of fluid obtained in chamber 52 and thereby in thebrake cylinder device 4 is increased to a certain relatively low degree,such as pounds, this pressure will move the piston ill in the directionof the left-hand into engagement with a gasket lBll whereupon spring 13will seat the check valve 72 so as to prevent further flow of fluidunder pressure from chamber 65 through the relatively large opening 68to the brake cyinder at the rate at which fluid is supplied to the brakeapplication and release passage by both the service and emergencyportion 8 After the check valve it. is seated as just de- :2."

scribed, fluid under pressure supplied to chamber it by the serviceandernergency portions will continue to flow to the brake cylinder 4 ata restricted rate by way of port l5 which lay-passes he seated checkvalve '12, thus providing for a continued but relatively slow increasein pressure in the brake cylinder l.

While fluid under pressure is being supplied to the brake cylinder as.iust described, the pressure in the emergency valve chamber 32 and.quick action chamber 33 is being gradually reduced to the atmosphere byway of the restricted port I02 through the vent valve piston Eli, and asa conse quence, the pressure in chamber 82 at the lefthand side ofdiaphragm ill in the timing valve device as is also beingcorrespondingly reduced. At the opposite side of diaphragm 8!, the checkvalve is at this time subject, in chamber 86, to the pressure of fluideilective in the brake application and release passage 7 l. and inchamber 87, out side of the seat rib 85, to brake cylinder pressure. Theparts of the timing valve device are so proportioned that after thepressure in the brake cylinder has been increased to a certain degree bythe relativel slow flow of fluid through the restricted part 75, theforces on the righthand side of the diaphragm will over-balance that onthe lefthand side and cause deflection of the diaphragm toward theleft-hand for unseating the check valve a l. With the check valve t lthus unseated. the brake application and re- 4 lease passage H isconnected through the choke equalization between the brake cylinder,auxiliary reservoir and emergency reservoir, as will be apparent.

From the above description it will now be noted that in effecting anemergency application of the brakes there is initially a limited rapidinshot of fluid under pressure to the brake cylinder l past the opencheck valve 12, followed by a relatively slow rate of supply governed bythe flow capacity of the restricted port T5, and finally there is anincrease in the rate of supply through choke 88 upon unseating of thetiming check valve 84, the final supply being by way of both the port 15and choke 88.

The purpose of the initial limited but rapid inshot of fluid pressure tothe brake cylinder is to provide an application of the brakes of suchdegree as to cause a gentle running in of the slack in a long freighttrain so as to avoid the creation of damaging shocks in the train. Thegradual supply to the brake cylinder by way of restricted port 15 thenprovides for a gradual increase in pressure in the brake cylinder i toinsure gentle gathering of the slack, and the final increase in the rateof supply provided by the restricted port ll: and choke B8 to the fullemergency degree to provide for prompt stopping of the train after theslack has been gathered. As before pointed out, the controlled increasein brake cylinder pressure in effecting an emergenc application of thebrakes on a long train as just described insures the stopping of thetrain without damaging slack action occurring.

In eifecting an emergency reduction in brake pipe pressure to cause anemergency application of the brakes as just described, the brake pipepressure in chamber HI will also be reduced at an emergency rate andquick action chamber pressure in chamber I33 of the changeover valveportion. 1 I will be reduced along with the pressure of fluid inemergency valve chamber 32 and quick action chamber 33 through the portI62 in the emergency vent valve piston 98. The capacity of port I92 invent valve piston 95 is however insuflicient to reduce the pressure invalve chamber !33 as fast as the brake pipe pressure is being reducedin. diaphragm chamber I3l so that sufficient differential of pressurewill be obtained on the diaphragm I30 for flexing it in a directiontoward the left-hand until brought to a stop by the follower engagingthe wall I46 of the casing. Flexing of the diaphragm I30 in adirectiontoward the'left-hand causes the stem H6 and attached slide valvto move in the same direction until brought to a stop by the diaphragmfollower engaging the casing. With the slide valve in this position apassage lBI extending through the stem I36 and slide valve I35 will moveinto registration with a passage I82 in the seat but this is ofno'consequence at this time since the passage 182 is lapped by slidevalve l2ll in the control mechanism I H! as shown.

Movement of the slide valve I35 to its lefthand position also cuts 01fcommunication between passages MI and I50 in the slide valve seat, butthis disconnectin of passages MI and I5!) in ordinary freight trainservice serves no useful purpose.

When, in effecting an emergency application of the brakes, the pressureof fluid in emergency valve chamber 32 and quick action chamber 33 issufliciently reduced through the choke H12 in the vent valve piston 99',the spring 9'1, acting on the vent valve 9|, will seat said valve andre- .turn the piston 99 to its normal position shown to provide forrecharging DI the brake equip- :ment :for :effecting ;a release ofibrakes after :an emergency application, whenever such i .:desired. Thevolume of the emergency valve chamber 32 and the quick action chamber 33are so related to the venting capacity of port I102 in the vent valvepiston '99 however that the vent valve 3| will .be held open 'for .asufiicient period of time to insure complete venting of all fluid fromthe brake pipe 5 in freight trains, to thereby insure an :emergencyapplication-of the brakes throughout .the length of the train.

ORDINARY FREIGHT TRAIN SERv1oERELEAsE or THE BRAKES AFTER AN EMERGENCYAPPLICATION In order to effect a release of the brakes after anemergency application, fluid under pressure is again supplied to thebrake pipe 5 and thereby the diaphragm chamber I3:I in the changeover-valve portion II, service piston chamber I9 and the emergency pistonchamber 3|.

It will be noted that since the quick action chamber pressure in valvechamber I33 is vented to the atmosphere during the emergency applicationan increase in brake pipe pressure in chamber I3I suflicient to overcomethe friction of the slide valve I35 will cause the diaphragm I30 andthereby the slide valve I35 to return to normal position in which theyare shown.

The consequent increasein pressure in the, service piston chamber overthe opposing reduced auxiliary reservoir pressure in valve chamber 22will return the piston I8 .and thereby theslide valves 24 and 28 totheir normal release position in which the brake cylinder 4 is opened tothe atmosphere as above described for effecting a release of the brakes.Also in this position fluid under pressure is again supplied from thebrake pipe to the valve chamber 22 and thence to the auxiliary reservoir2 and emergency reservoir 3 for recharging 'same to the pressure in thebrake pipe.

The increase in brake pipe pressure on the emergency piston '30 willreturn same and thereby the slide valves 39 and 35 to their normalpositions in which the valve chamber 32, the quick action chamber 33 andthe 'valve chamber I33 in the changeover valve portion I I will berecharged with fluid at the pressure in the brake pipe.

Upon this recharging of the emergency .Valve chamber 32 thecorresponding increase in pressure in chamber 82 at the left-hand sideof the timing diaphragm III will return the check valve 84 into sealingcontact with seat rib 85, and the pressure both inside and outside ofsaid seat It-willalso benoted that the safety-valve device I40 :does notinterfere with or change theoper- -ation of the brake controlling valvedevice I in ordinary freight train service in any way,so'that itsoperating characteristics in both service and an emergency applicationof the brakes remain like that of the usual AB brake equipment.

Short train high speed service When a car equipped with the brakecontrolling valve device I is coupled into a short high speed passenger,freight or express train, the charging of the signal pipe on the trainwill provide fluid under pressure in chamber IIS of the control valvemechanism IIO of the changeover portion II. This pressure acting on thediaphragm II5 will deflect same in a direction toward the right-hand andthus, through the medium of stem I22, move the slide valve I20 from itsordinary freight train operating position in which it is shown in thedrawings to the short train operating position.

rib will be reduced to that of the atmosphere along with the venting offluid under pressure from the brake cylinder 4. In other words, thedifferent parts of the brake controlling valve device I will now beconditioned in the positions in which they are shown in the drawings.

SUMMARY Ordinary freight train service In this short train operatingposition of the slide valve I20, cavity I44 therein connects passage I82leading from the seat for the slide valve I35 of the valve mechanism IIIto a passage I83 leading to the atmosphere for a purpose presentlydescribed. In this position of the slide valve I20 the cavity I45therein connects a passage I84 leading from the application and re-.lease passage II to a passage I85 leading to the brake cylinder passage65 thereby opening a bypass around the restricted port I5 in theemergency delay valve mechanism 50 and the restricted port in the timingvalve mechanism 00. As a result, when an emergency application of thebrakes is effected as above described, fluid under pressure will besupplied to the brake cylinder 4 by way of application and releasepassage II, passage I84, cavity I45, in the slide valve I20 of thecontrol valve mechanism IIO, passage I and brake cylinder passage 65 atthe relatively rapid rate desired in high speed short train operation toensure prompt stopping of 4 the train; the emergency delay mechanism 50being thus rendered ineffective to limit the rate of supply of fluid tothe brake cylinder although it will operate in high speed trainoperation in the same manner as in ordinary freight train service asabove described.

Upon an emergency reduction in brake pipe pressure, the valve mechanismI I I of the changeover valve portion II is caused to move from itsnormal position in which it is shown to its other operating position aspreviously described in connection with an emergency application of thebrakes on a long train. With the slide valve I35 in its other operatingposition, port I8I which extend through the stem I36 and slide valve I35connects passage I82 to valve chamber I33 so that fluid under pressurein the connected emergency valve chamber 32 and the quick action chamber33 is vented to the atmosphere by way of passages 34 and I34, chamber133 in the valve mechanism III port I8I in stem I36 and slide valve I35,passage I82, choke I85 in said passages, cavity I44 in the slide valveI20 of the control valv mechanism H0 and atmospheric passage I83 inaddition to the venting of fluid under pressure through port I02 in thevent valve piston 99 and thus permit quicker release of the brakes afteran emergency application than is obtainable on ordinary freight trainsas above mentioned.

From the foregoing description of the operation of the valve mechanismH! in ordinary freight train service it will be understood that theslide valve I 35 of this mechanism will remain in its normal position atall times except when the brake pipe pressure acting in chamber 13! isreduced at a rate exceeding that effected when effecting a serviceapplication of the brakes. With the slide valve its in its normalposition a shown the safety valve hill is connected by way of passage14! and cavity H29 in the slide valve I35 to the passage I59 and withthe chamber 4 iii of the valve mechanism I 10 charged with fluid atsignal pipe pressure the slide valve l2!) in valve mechanism llil willbe positioned so that cavity I45 therein will connect passage IE!) topassage I84 and thereby the brake application and release passage H.With this communication established it will be apparent that the safetyvalve M is connected to the brake cylinder 4 and will be effective tolimit the degree of pressure obtained in the brake cylinder i upon aservice application of the brakes on short high speed passenger freightor express trains which, as hereinbefore mentioned, normally carry 110pounds in the brake pipe. When an emergency reduction in brake pipepressure is effected, however, corresponding venting of fluid underpressure from diaphragm chamber 13! will permit the slower reducingquick action pressure in chamber I33 and acting'on the opposite side ofthe diaphragm to move said diaphragm and associated emergency portionsof the brake controlling valve device are identical in construction andoperation with corresponding parts shown in Fi 1 of the drawings, andsimilar reference numerals are therefore employed to indicate similarparts in both embodiments.

The changeover valve portion Zlll comprises essentially the parts of thechangeover valve device described in the aforementioned McClure 101application and for this reason will be but briefly stem l35 and slidevalve i35 to its left-hand position as hereinbefore described. With theslide valve in its left-hand position it disconnects the passage Hi0from the passage MI and thereby the safety valve M!) from the brakecylinder 4, so as to render the safety valve ineffective and thusprovide for obtaining in the brake cylinder 4 the usual high emergencypressure required for prompt stopping of the train.

It will be understood that to recharge the equipment and to effect arelease of the brake following either a service or an emergencyapplication of the brakes on a short train, the brake pipe pressure willbe increased in the usual manner and the control valve device I willoperate in the same manner as hereinbefore described in connection withordinary freight train service.

From the foregoin it will be noted that in the embodiment of theinvention shown in Fig. 1, the addition of the filling piece or memberin and changeover valve portion H to the usual AB brake equipment, suchas disclosed in the aforementioned Farmers patent, provide for use ofthis brake equipment on cars which are required to operate in bothordinary freight train service and high speed relatively short passengerfreight or express service.

Embodiment-Figure 2 In Fig. 2 of the drawings there is illustrated abrake equipment employing a brake controlling valve device embodyinganother form of the invention. In this embodiment of the invention, achangeover valve portion 2M including a brake cylinder pressure limitingvalve device 293 and a quick application valve device 28 3 such asshown, described and claimed in the McClure application, Serial No.460,045, filed September 29, 1942, now Patent No. 2,352,277. dated June2'7, 1944, together with an auxiliary vent valve portion 205, issubstituted for the changeover valve ll, previously described inconnection with the embodiment shown in Fig. 1. The other parts of thebrak apparatus including the service and Iii) described in the presentapplication.

' Description The limiting valve device 203 comprises two oppositelydisposed flexible diaphragms 2l2 and vcommunication with the atmospherethrough a restricted port 2|6. At the opposite side of diaphragm 2 l 2is a chamber 2 I I which is in constant open communication with thebrake pipe 5 by way of a passage 2l8, a passage ZIBa and passage I32which latter passage, as hereinbefore described "in connection with theequipment shown in Fig. 1, extends through the filling piece H] where itis connected with the passage 20. At the opposite side of diaphragm 2|3is a chamber 2!!! which is ,cOnnected to the safety valve Hill by way ofa passage 22!].

The limiting valve device 203 further comprises a check valve 22!contained in a chamber 222 which is connected through a passage 223, a

, chamber 224, a passage 225 and connected passage I85 leading to thebrake cylinder passage 85. This check valve has a fluted stem 225slidably mounted in a bushing 22! mounted in a wall separating chambers2H! and 222, said check valve and stem being arranged in coaxial"relation with the diaphragm 2l3 with the end of said stem engaging saiddiaphragm. A spring 228 acting on the check Valve 22! is provided forurging same into sealing engagement with one end of the bushing 22'! forclosing communication between chambers. 222 and chamber til The quickapplication valve device 2M comprises two flexible diaphragms 230 and23! arranged in coaxial relation and operatively connected together by astrut 232. The diaphragm tii is of greater area than diaphragm 231 andbetween these diaphragms is a chamber 233 which is open to theatmosphere by way of chamber 255 and port Zlfi. At the opposite face ofdiaphragm 230 is a chamber"234 which is con- .nected through passage234a to the passage lil leading to the signal pipe 6. At the oppositeside of diaphragm 23! is the chamber 224 which is open to the brakecylinder 4 by Way of passages 225, N and brake cylinder passage 55.

The quick application valve device 204 further comprises a check valve235 contained in a chamber 237 which is connected by passage 237a andpassage I84 to the application and release passage H. The check valve238 has a fluted stem 238 slidably mounted in a bushing 239 chamber 23'!acts on the check valve 235 for urging same into sealing contact withthe adjacent end of bushing 239. Deflection of the diaphragms 230 and23! in the direction of the right-hand will unseat the check valve 236from the end of bushing 239.

The auxiliary vent valve portion 265 comprises a sectional casing 253which in the present embodiment of the invention is mounted on thecasino section ZGI with a sealing gasket 25! interposed between. Thecasing 250 contains a vent valve mechanism comprising two flexiblediaphragms 252 and 253 which are spaced apart and clamped around theirperipheries in coaxial relation forming an intermediate chamber 254which is in constant open communication with the quick action chamber 33and emergency vent valve chamber 32 through a passage 255 and passageI34. The diaphragm 252 is of greater area than diaphragm 253 and at itsouter face is a chamber 256 which is in constant open communicationthrough a passage 251. passage I32 and connected passage 20 with thebrake pipe 5. At the outer face of the smaller diaphragm 253 is a valvechamber 258 containing a valve piston 259 which is slidahly mounted in abore 265 in the casing, which bore is open at one end to chamber 258 andat the other end to a chamber 28!. The valve piston 259 is provided witha stem 262 which is operatively connected to the diaphragms 252 and 253,in any suitable manner. for movement therewith. A spring 263 dis posedin chamber 256 acts through the medium of a diaphragm follower 264 onthe diaphragm (It andthereby the stem 262 and diaphragm for urging saiddiaphragms. stem and thereby the valve piston 259 to the position inwhich they are shown in the drawings. With the valve piston in theposition shown it engages a seat rib which surrounds a passage 264 whichis connected to the quick action chamber 33 and emergency valve chamber32 through a chamber 266. passage 255, passage I34 and passage 34.

The vent valve mechanism further comprises a flexible diaphragm 231having at one side a chamber 263 which is in constant open communicationwith the signal pipe 6 by way of passages 234a and Hi. At the oppositeside of the diaphragm 2G! is the chamber ZBI which is in constant opencommunication with the atmosphere through a passage 21!. Contained inchamber 26! and engaging the diaphragm 257 is a diaphragm follower 212provided with a plurality of spaced legs 213 which extend through asection 274- of the casing which projects into chamber 23!. The outerends of these legs are spaced away from the valve piston 259 in theposit on in which they are shown, which position is the one thediaphragm 23'! and follower will assume when the chamber 268 is atatmospheric pressure. This is the position which the diaphragm 26'! anddiaphragm follower 212 will assume in ordinary freight trains on whichthere is no use for a signal pipe.

OPERATION Ordinary freight train service If a car provided with thisequipment is coupled into an ordinary freight train, the signal pipe 6on the car will be devoid of fluid under pressure and chamber 234 at oneside of diaphra m 233 in the application valve device 234 as well aschamber 268 at one side of diaphragm 23'. in the auxiliary vent valveportion 205 will therefore be open to the atmosphere. Under theseconditions the spring 240 disposed in chamber 23'! of the applicationvalve device will maintain the check valve 236 seated against the end ofthe bushing 239, and the spring 263 disposed in chamber 256 of theauxiliary vent valve device 205 will maintain the valve piston 259seated against the seat rib 285.

In initially charging the equipment, fluid under pressure supplied tothe brake pipe 5 flows to the various chambers in the service portion 8and emergency portion 9 of the brake controlling valve device as well asto the auxiliary and emergency reservoir 3 and 4 in substantially thesame manner as described under initial charging in ordinary freighttrain service in connection with the embodiment of the invention shownin Fig. l of the drawings. luid under pressure supplied to the brakepipe flows therefrom to the diaphragm chamber 2!! in the limiting valvedevice and also to the diaphragm chamber 258 in the auxiliary vent valvedevice 205 by way of passage and pipe 2|, passages 20, I32 and 2l8a. Itmight here be mentioned that brake pipe pressure in chamber 2H acting onthe diaphragm 212 will deflect same and thereby the diaphragm 213 in thedirection of the right-hand to unseat the check valve 22! and maintainin this position until such time as the brake pipe pressure is reducedto a chosen low degree, i. e., below that which results from a, fullservice reduction. Such a reduction occurs upon an emergency reductionin brake pipe pressure. Fluid at brake pipe pressure supplied in theusual manner to the emergency valve chamber 32 and quick action chamber33 of the brake controlling valve device flows therefrom to passage 534from whence it flows by way of passage 255 to chamber 254 between thediaphragms 252 and 253 in the auxiliary vent valve portion 205. Fluidunder pressure supplied to passage 255 also flows to chamber 256 in theauxiliary vent valve portion 295.

With chamber 256 charged to brake pipe pressure and chamber 254 at theopposite side of the diaphragm 252 charged to quick action chamberpressure the spring 263 plus the brake pipe pressure in chamber 256 willmaintain the diaphragm assemblage including diaphragms 252 and 253. stem252 and valve piston 253 in the position shown. The change-over valveportion 2Gl thus conditioned. will in no Way alter or modify the usualoperating characteristics of the service and emergency portions of thebrake controlling valve device, and as a consequence the brake equipmenton the car will then operate in its various positions to control the carbrakes in harmony with the control of the brakes on all other cars inthe train in identically the same manner as hereinbefore described inconnection with the embodiment of the invention shown in Fig. 1.

Short train high. speed service When a car equipped with the brakecontrolling valve device 200 shown in Fig. 2 is coupled into a shorthigh speed passenger freight or express train, the charging of thesignal pipe on the train will provide fluid under pressure in chambers234 and 268 of the application valve device 234 and the auxiliary ventvalve device 235, respectively. The signal pipe pressure acting on thediaphragm 233 will deflect same and thereby the diaphragm 21 in thedirection of the right-hand to unseat the check valve 235. The signalpipe pressure acting on the diaphragm service reduction in brake pipepressure.

251 will cause it to deflect in a direction toward the left-hand.Deflection of the diaphragm 261 in this direction causes the diaphragmfollower 2l2 to move in the same direction until broughtto a stop by thelegs 2'l3 engaging the valve piston 25%.

The opening of check valve 23% connects the brake application andrelease passage ll through passage iS-i, passage 23hr, chamber 23?, pastunseated check valve 236, chamber 224, passage 225i and passage I85 tothe brake cylinder passage 55 thereby opening a by-pass around the brakecylinder build-up control "alve mechanism 50. As a result, whenanemergency application of the brakes is effected, fluid under pressurewill be supplied to the brake cylinder t past the check valve 236 at therelatively rapid rate desired in high speed short train service.

When an emergency reduction in brake pipe pressure is eilected, thebrake pipe pressure in chamber 256, acting on one side of diaphragm andthe quick action chamber pressure in chamber 255, acting on the oppositeside of the diaphragm, will be reduced. It will be understood, however,that the reduction in brake pipe pressure in chamber 256 will be at amore rapid rate than the reduction in quick action chamber pressure inchamber 254, thus the higher pressure in chamber 25d, tending to flexthe diaphragm 252 in a direction toward the left-hand plus signal pipepressure in chamber 253 acting through the medium of the follower 232,causes the diaphragm assemblage including diaphragms 2i"? and 253, stem25? and valve piston $259 to move in a direction toward the left-handagainst the opposing pressure of spring 263 until brought to a stop bythe valve piston 259 engaging a stop 2%. With the valve piston in thisposition it will of course be out of engagement with the seat rib sothat communication is established be tween chambers 2% and 266. With thevalve piston thus unseated fluid under pressure in the emergency valvechamber quick action chamber and chamber 254 in the auxiliary vent valvedevice 265 is vented to the atmosphere by way of passage 255, chamber265, passage 2% past unseated valve piston 259, chamber 264 and passageFill. This venting is in addition to the venting of fluid under pressurethrough port it? in the vent valve piston 99 and thus permits a quickerrelease of the brakes after an emergency application than is obtainablein ordinary freight train service.

A hereinbefore mentioned, the brake pipe pressure in chamber 2H of thelimiting valve portion 203 of the change-over portion Zlll holds thecheck valve 22 i open until such time as the brake pipe pressure isreduced to a chosen low degree. As a result, the safety valve its willbe effective to limit to the desired degree the pres sure obtained inthe brake cylinder lupcn a full When an emergency reduction in brakepipe pressure is effected, however, the corresponding venting of fluidunder pressure from diaphragm chamber 2!! will permit brake cylinderpressure and the pressure of spring 228 in. chamber 222 acting on thecheck valve 22! to seat said check valve and thereby disconnect thesafety valve device l-tl! from the brake cylinder l so as to render thesafety valve device ineffective, thus providing for the obtaining in thebrake cylinder d of the usual high emergency pressure required forprompt stopping of the train in high speed service.

When it is desired to recharge the equipment and to effect a release ofthe brakes following an emergency application, the pressure in the brakepipe 5 is increased and the service and emergency 1 portions of thebrake controlling valve device 200 operate in the same manner ashereinbefore described in connection with the brake controlling valvedevice I shown in Fig. 1. The consequent increase in pressure of fluidin the chamber 256 of the auxiliary vent valve device 2E5, plus thepressure of spring 263 acting on the diaphragm 252 causes the diaphragmassemblage including diaphragms 252 and 253, stem 262 and valve piston259 to move in the direction of the right-hand until brought to a stopby the valve piston 259 coming into contact with its seat rib 265 thusclosing communication between chambers 26l and 266 and therebycommunication between the emergency valve chamber 32 and quick actionchamber 33 and the atmosphere. With this communication cut off, thequick action chamber and emergency valve chamber are again recharged inthe usual manner with fluid at brake pipe pressure. In this connectionit will be noted that when the pressure in the brake pipe and therebythe chamber 256 is increased to effect a release of the brakes followingan emergency application, the quick action chamber and thereby thechamber 254 in the auxiliary vent valve device 205 is at atmosphericpressure so that only a slight increase in brake pipe pressure isrequired in chamber 256. to effect movement of the valve piston intoengagement with the seat rib 265 as shown and thus permit the quickaction chamber to be recharged with fluid at brake pipe pressure withoutany delay.

SUMMARY It will now be noted that both brake control- 1 ling valvedevices I and 200. shown in Figs. 1 and 2, respectively, of the drawingsare automatically adjustable or conditionable for either ordinaryfreight train service or short fast passenger freight or express trainservice to provide the desired brake operatingcharacteristics called forin each of said services. With either of the brake controlling valvedevices the automatic conditioning for short high speed train service isobtainable by the pressure employed in the signal pipe of such trains,while the conditioning for ordinary freight train service is obtainableautomatically due to the absence of a signal pipe on such trains.

Having now described our invention what we claim as new and desire tosecure by Letters Patent is:

1. In a fluid pressure brake, in combination, a brake pipe, a signalpipe, a quick action chamber, movable abutment means subject to signalpipe pressure and the opposing pressures of the brake pipe and quickaction chamber and operative upon an emergency reduction in brake pipepressure with the signal pipe charged with fluid under pressure to -opena vent from the quick action chamber, and resilient means associatedwith said movable abutment means for rendering said mov able abutmentmeans inefiective to open said. vent from the quick action chamber uponan emergency reduction in brake pipe pressure with the signal pipedevoid of fluid under pressure.

2. In a fluid pressure brake, in combination. a brake pipe, 9. signalpipe, a quick action chamber, valve means including a first movableabutment subject to signal pipe pressure and a second movable abutmentsubject to the opposing pressures of the brake pipe and quick .actionchamber, said valve means being operative upon an emergency reduction inbrake pipe pressure with the signal pipe charged with fluid underpressure to open a vent from the quick action chamber and spring meansfor rendering said valve means ineffective to open the vent from thequick action chamber upon an emergency reduction in brake pipe pressurewith the signal pipe devoid of fluid under pressure.

3. In a fluid pressure brake, in combination, a brake pipe, a signalpipe, a quick action chamber, a communication through which fluid underpressure may be vented from the quick action chamber, valve means forcontrolling said communication, movable abutment means for controllingsaid valve means, said movable abutment means comprising a firstflexible diaphragm subject to signal pipe pressure and a second flexiblediaphragm subject to the opposing pressures of the brake pipe and quickaction chamber and operative upon an emergency reduction in brake pipepressure when the signal pipe is charged with fluid under pressure toeffect operation of said valve means to open said communication, andmeans for rendering said movable abutment means ineffective to effectoperation of said valve means to open said communication upon anemergency reduction in brake pipe pressure with the signal pipe devoidof fluid under pressure.

4. In a fluid pressure brake, in combination, a brake pipe, a signalpipe, a quick action chamber, an emergency valve device controlled bythe opposing pressures of said brake pipe and quick action chamber andoperative upon an emergency rate of reduction in brake pipe pressure toeffect an emergency application of the brakes and to establish acommunication for releasing fluid under pressure from said chamber,means for restricting the release of fluid under pressure from saidchamber to provide for a certain rate of reduction in pressure in saidchamber, other valve means subject to signal pipe pressure and theopposing pressures of the brake pipe and quick action chamber andoperative upon an emergency reduction in brake pipe pressure with thesignal pipe charged with fluid underpressure to open an auxiliarycommunication for releasing fluid under pressure from said chamber toprovide for a faster rate of reduction in pressure in said chamber thanprovided for by said restricted means, and means for rendering saidother valve means ineffective to open said auxiliary communication uponan omergency reduction in brake pipe pressure with the signal pipedevoid of fluid under pressure.

5. In a fluid pressure brake, in combination, a brake pipe, a signalpipe, a quick action chamber, an emergency valve device controlled bythe opposing pressures of said brake pipe and quick action chamber andoperative upon an emergency rate of reduction in brake pipe pressure toeffect an emergency application of the brakes and to establish acommunication for releasing fluid under pressure from said chamber,means for restricting the release of fluid under pressure from saidchamber to provide for a certain rate of reduction in pressure in saidchamber, other valve means subject to signal pipe pressure and theopposing pressures 'of the brake pipe and quick action chamberandoperative upon an emergency reduction in brake pipe pressure with thesignal pipe charged with fluid under pressure to also release fluidunder pressure from said chamber to accelerate the rate ill) ofreduction in the pressure of fluid in the chamher, a choke forrestricting the release or fluid under pressure from said chamber bysaid other valve means said other valve means being rendered ineffectiveto release fluid under pressure from said chamber upon an emergencyreduction in brake pipe pressure when the signal pipe is devoid of fluidunder pressure.

6. In a fluid pressure brake, in combination, a brake pipe, a signalpipe, a quick action chamber, an emergency valve device controlled bythe opposing pressures of said brake pipe and quick action chamber andoperative upon an emergency rate of reduction in brake pipe pressure toeffect an emergency application of the brakes and to establish acommunication for releasing fluid under pressure from said chamber.means for restricting the release of fluid under pressure from saidchamber to provide for a certain rate 01f reduction in pressure in saidchamber, another communication for releasing fluid under pressure from,said quick action chamber, valve means having a normal position forclosing said other communication and another position for opening same,and movable abutment means subject to signal pipe pressure and theopposing ressures of the brake pipe and quick action chamber forcontrolling the position of said valve means and operative upon anemergency reduction in brake pipe pressure only when said signal pipe ischarged with fluid under pressure to position said valve means in itscommunication opening position.

7. In a fluid pressure brake, in combination, a brake pipe, a signalpipe, a quick action chamber, a source of fluid under pressure, acontrolling valve device operative upon a reduction in brake pipepressure to supply fluid under pressure from said source through acommunication to effect an application of the brakes, means operative tocontrol the flow of fluid under pressure through said communication toprovide a certain degree of braking in a certain interval of time, aby-pass communication around said means to provide said certain degreeof braking in a shorter interval of time, a passage through which fluidunder ressure may be released from said chamber, valve means subject tosignal pipe pressure and the opposing pressures of the brake pipe andquick action chamber and operative upon an emergency reduction in brakepipe pressure with the signal pipe charged with fluid under pressure toopen said by-pass communication and said passage, and means forrendering said valve means ineffective to open said bypass communicationand said passage upon an emergency reduction in brake pipe pressure withthe signal pipe devoid of fluid under pressure.

8. In a fluid pressure brake in combination, a brake pipe, a brakecylinder, a service valve device operative upon either a service or anemergency rate of reduction in brake pipe pressure to supply fluid underpressure to said brake cylinder for effecting an application of brakes,a quick action chamber, an emergency valve device controlled by theopposing pressures of 'said brake pipe and quick action chamber andoperative upon a service reduction in brake pipe pressure to effect aservice rate of reduction in pressure in said quick action chamber andupon an emergencyreduction in brake pipe pressure to supply fluid underpressure to said brake cylinder and to also effect venting of fluidunder pressure from quick action chamber at a chosen rate, a safetyvalve, a signal pipe, valve means subject to signal pipe pressure andthe opposing pressures of the brake pipe and quick action chamber havinga normal position for connecting said safety valve to said brakecylinder and operative from said normal position only upon an emergencyreduction in brake pipe pressure with the signal pipe charged With fluidunder pressure to to supply fluid under pressure to said brake cylinderfor effecting an application of brakes, a quick action chamber, anemergency va1ve device controlled by the opposing pressures of saidbrake pipe and quick action chamber and operative upon a servicereduction in brake pipe pressure to effect a service rate of reductionin pressure in said quick action chamber and upon an emer gencyreduction in brake pipe pressure to supply fluid under pressure to saidbrake cylinder and to also effect venting of fluid under pressure from5:

quick action chamber at a chosen rate, valve means for retarding theflow of fluid under pressure from said service and emergency valvedevice to said brake cylinder, said valve means being controlled by saidemergency application valve device and being rendered effective therebyupon an emergency reduction in brake pipe pressure and ineffective atother times, a by-pass communication around said valve means to providefor a faster flow of fluid under pressure to the brake cylinder, asafety valve, a signal pipe, valve means subject to signal pipe pressureand the opposing pressures of the brake pipe and quick action chamberhaving a normal position for closing said by-pass communication and forconnecting said safety valve to said brake cylinder and operative fromsaid normal position only upon an emergency reduction in brake pipepressure with the signal pipe charged with fluid under pressure to opensaid by-pass communication and to disconnect said safety valve from thebrake cylinder and to open a second vent from said quick action chambervto increase the rate of reduction in pressure therein, and means forrendering said valve means ineffective to open the by-pass communicationand the second vent from the quick action chamber upon an emergencyreduction in brake pipe pressure with the signal pipe devoid offluifunder pressure.

10. In a fluid pressure brake, in combination, a brake pipe, a brakecylinder, an auxiliary reservoir, an emergency reservoir, a quick actionchamber, a service valve device operative upon either a service or anemergency reduction in brake pipe pressure to supply fluid underpressure from said auxiliary reservoir to said brake cylinder, anemergency valve device operative upon a service reduction in brake pipepressure to effect a reduction in pressure in said quick action chamberand upon an emergency reduction in brake pipe pressure to supply fluidunder pressure from said emergency reservoir to said brake cylinder andalso effect venting of fluid under pressure from the quick actionchamber at a chosen rate, a safety valve for limiting the emergencyvalve devices controlling communication between said safety valve deviceand brake cylinder, and for also controlling said auxiliary passage,said valve means being subject to signal pipe pressure and the opposingpressures in the brake pipe and quick action chamber and operative onlyupon an emergency reduction in brake pipe pressure with the signal pipecharged with fluid under pressure to open said auxiliary passage and toclose said communication,

11. In a fluid pressure brake, in combination, a brake pipe, a signalpipe, a quick action chamber, an emergency valve device controlled bythe opposing pressure of said brake pipe and quick action chamber andoperative upon an emergency rate of reduction in brake pipe pressure toeffect an emergency application of the brakes and to establish acommunication for releasing fluid under pressure from said chamber,means for restricting the release of fluid under pressure from saidchamber to provide for a certain rate of reduction in pressure in saidchamber, an auxiliary communication for releasing fluid under pressurefrom said chamber to provide for a faster rate of reduction in pressurein said chamber than provided for by said restricted means, valve meanscontrolled by the opposing pressure of said brake pipe and quick actionchamber and operative by the pressure of fluid in said quick actionchamber upon an emergency reduction in brake pipe pressure to open saidauxiliary communication, a spring, and means controlled by the opposingpressures of fluid in said signal pipe and of said spring for renderingsaid valve means efiective to open said auxiliary communication uponeffecting an emergency reduction in brake pipe only .when said signalpipe is charged with fluid under pressure.

12. In a fluid pressure brake, in combination, a brake pipe, a signalpipe, a quick action chamber, an emergency valve device controlled bythe 0pposing pressure of said brake pipe and quick action chamber andoperative upon an emergency rate of reduction in brake pipe pressure toeffect an emergency application of the brakes and to establish acommunication for releasing fluid under pressure from said chamber,means for restricting the release of fluid under pressure from I saidchamber to provide'ior a certain rate of reduction in pressure in saidchamber, an auxiliary communication for releasing fluid under pressurefrom said chamber to provide for. a faster rate of reduction in pressurein said chamber than provided 'for by said restricted means, valve meansincluding a spring and a movable abutment subject to the opposingpressures of said signal pipe and of said spring for opening saidauxiliary communication with said signal pipe charged with fluid underpressure and for maintaining said auxiliary communication closed whensaid signal pipe is void of fluid under pressure, and other valve meansinterposed in said auxiliary communication subject to the opposingpressures of said brake pipe and quick action chamber having a normalposition for closing said auxiliary communication and bein operative byquick action chamber pressure upon an emergency reduction in brake pipepressure to open said auxiliary communication.

13. In a fluid pressure brake, in combination,

a brake pipe, a signal pipe, a quick action chamber, an emergency valvedevice controlled by the opposing pressure of said brake pipe and quickaction chamber and operative upon an emergency rate of reduction inbrake pipe pressure to effect an emergency application of the brakes andto establish a communication for releasing fluid under pressure fromsaid chamber, means for restricting the release of fluid under pressurefrom said chamber to provide for a certain rate of reduction in pressurein said chamber, an auxiliary communication for releasing fluid underpressure from said chamber to provide for a faster rate of reduction inpressure in said chamber than provided for by said restricted means, andvalve means interposed in said auxiliary communication for controllingthe flow of fluid under pressure therethrough, said valve 'meansincluding movable abutment means subject to the opposing pressures ofsaid brake pipe and quick action chamber and operative by quick actionchamber pressure upon an emergency reduction in brake pipe pressure whensaid signal pipe is charged with fluid under pressure to open saidauxiliary communication and operative upon a subsequent slight increasein brake pipe to close said auxiliary communication.

14. In a fluid pressure brake, in combination, a brake pipe, a signalpipe, a quick action chamber, an emergency valve device controlled bythe opposing pressure of said brake pipe and quick action chamber andoperative upon an emergency rate of reduction in brake pipe pressure toeffect an emergency application of the brakes and to establish acommunication for releasing fluid under pressure from said chamber,means for restricting the release of fluid under pressure from saidchamber to provide for a certain rate of reduction in pressure in saidchamber, an auxiliary communication for releasing fluid under pressurefrom said chamber to provide for a faster rate of reduction in pressurein said chamber than provided for by said restricted means, valve meanssubject to the opposing pressures of brake pipe and quick action chamberand operative by quick action chamber pressure upon an emergencyreduction in brake pipe pressure to open said auxiliary communicationand operative upon a subsequent slight increase in brake pipe to closesaid auxiliary communication, and valve means interposed in saidauxiliary communication subject to the opposing pressures of the signalpipe and a spring for selectively renderin said valve means efiective orineffective to open sai'd auxiliary communication.

15. In a fluid pressure brake, in combination, a brake pipe normallycharged with fluid under pressure, a quick action chamber normallycharged with fluid under pressure, a vent communication from saidchamber, a signal pipe, a valve piston having a normal position forclosing said vent communication and movable to another position foropeningsaid vent communication, and actuating means for moving saidvalve piston from said normal position to said other position, saidactuating means comprising a first movable abutment subject to signalpipe pressure and a second movable abutment subject to quick actionchamber pressure and the opposing pressure of fluid in the brake pipeand a spring, said first and said second movable abutment cooperating toactuate said valve piston from said normal to said other position uponeffecting an emergency reduction in brake pipe pressure only when thesignal pipe is charged with fluid under pressure.

16. In a fluid pressure brake, in combination, a brake pipe normallycharged with fluid under pressure, a quick action chamber normallycharged with fluid under pressure, a vent communication from saidchamber, a signal pipe, a valve piston having one position for openingsaid vent communication and another position for closing said ventcommunication, means for controlling said valve piston comprising a pairof movable abutments one of said pair being subject to signal pipepressure and the other of said pair being subject to the opposingpressure of the brake pipe and the quick action chamber, said abutmentscooperating upon an emergency reduction in brake pipe pressure with thesignal pipe charged with fluid under pressure to actuate said valvepiston to said one position, and spring means for actuating said valvemeans to said other position upon a subsequent slight increase in brakepipe pressure.

17. In a fluid pressure brake, in combination, a brake pipe normallycharged with fluid under pressure, a signal pipe charged with fluidunder pressure in one class of train service and devoid of fluid underpressure in another class of train service, valve means operative toestablish a venting communication from the quick action chamber, saidvalve means being conditioned by signal pipe pressure when the signalpipe is charged for providing for the venting of fluid under pressurefrom the quick action chamber, and said valve means being subject to theopposing pressures of the brake pipe and quick action chamber andoperative upon a reduction in brake pipe pressure for effecting theventing of fluid from the quick action chamber, and means for renderingsaid valve means ineffective to provide for the venting of fluid underpressure from the quick action chamber upon an emergency reduction inbrake pipe pressure with the signal pipe devoid of fluid under pressure.

JOHN CANE'I'TA. GHARLES F. HAMMER.

